THYROID RADIOLOGY AND NUCLEAR MEDICINE
THYROID
Volume 21, Number 2, 2011
ª Mary Ann Liebert, Inc.
DOI: 10.1089/thy.2010.0090
Current Safety Practices Relating to I-131 Administration
for Diseases of the Thyroid: A Survey of Physicians
and Allied Practitioners
Carol Greenlee,1 Lynn A. Burmeister,2 Robert S. Butler,3 Charlotte H. Edinboro,4 Shannon McIntyre Morrison,3
and Mira Milas;5 The American Thyroid Association Radiation Safety Precautions Survey Task Force
Background: There is little information about the individual safety instructions provided by healthcare professionals to patients receiving radioactive iodine (I-131) therapy for the treatment of benign and malignant
thyroid disorders or about whether these instructions are consistent across medical specialties. Currently, no
national guidelines exist to standardize safety instructions related to I-131 administration. Here, we examine the
spectrum of I-131 safety practices in contemporary use.
Methods: Members of major societies of physicians and allied specialists who treat patients with thyroid disorders were invited to complete a 27-question online survey about safety practices related to I-131 administration. Data from questionnaires were analyzed by type of safety recommendation and grouped according to
provider specialty and geographic location.
Results: A total of 311 endocrinologists, surgeons, nuclear medicine radiologists, and allied health professionals
completed questionnaires. They indicated that patients often receive instruction from more than one treating
specialist. The decision to hospitalize a patient for treatment and the length of stay were determined by the
patient’s social situation and the dose of I-131 administered. Starting at I-131 doses between 259 and 1073 MBq (7
and 29 mCi), over 60% of respondents advised avoiding contact with children, sexual activity, and breastfeeding,
with the latter recommendation continuing beyond 48 hours after treatment. Personal hygiene, laundry, and
meal preparation precautions varied across respondents. Over 90% of respondents used serum or urine testing
to screen for pregnancy status. Precautions to delay parenthood were given more often to female than male
patients (90% vs. 60%), with a minimum recommended delay of 6 months. About 20% of respondents considered insurance coverage as a factor in selecting outpatient versus inpatient I-131 therapy, and this consideration
varied geographically.
Conclusion: A wide variety of safety recommendations are given to patients who receive I-131. To our
knowledge, this survey represents the ﬁrst organized inquiry into safety practices related to I-131 administration.
The diversity of responses suggests an opportunity for multispecialty collaboration in deﬁning more uniform
recommendations for patient safety instructions during and after I-131 treatment.
Introduction
I
n 2006, the American Thyroid Association (ATA)
prepared a Position Commentary in response to a challenge
to the U.S. Nuclear Regulatory Commission’s guidelines for
public safety regarding exposure to patients treated with radioactive iodine (I-131) (1). During the preparation of that
commentary, it became apparent that great diversity existed
in the safety precautions recommended by the ATA committee members to patients receiving I-131. Precautions varied from very minimal to very rigorous procedures, the choice
of which appeared to be based on tradition, local regulations,
level of personal concern, and payers’ acceptance or denial of
certain procedures. A survey was conducted to identify the
safety advice most commonly provided to patients and to
quantify the differences among current practices.
1
Western Slope Endocrinology, Grand Junction, Colorado.
Division of Endocrinology and Diabetes, University of Minnesota, Minneapolis, Minnesota.
3
Quantitative Health Sciences, Cleveland Clinic, Cleveland, Ohio.
4
Health Sciences Group, Exponent, Inc., Menlo Park, California.
5
Department of Endocrine Surgery, Endocrinology and Metabolism Institute, Cleveland Clinic, Cleveland, Ohio.
2
151
152
GREENLEE ET AL.
The primary objective of the survey was to elicit information concerning recommendations for I-131 safety protocols
for patients treated for hyperthyroidism, goiter, and thyroid
cancer. A secondary objective was to identify differences in
recommendations due to geographical location or professional association. The overall goal was to obtain a measure of
clinical safety practices related to I-131 treatment. To our
knowledge, this is the ﬁrst survey of its kind to capture contemporary clinical practices. Our hypothesis was that these
practices vary widely with clinician specialty. In reporting
existing practices, we proposed to determine whether these
practices illustrate a need for the development of a common
set of safety precaution recommendations to be provided to
patients, their families, and caregivers following I-131 therapy, because these are lacking in published literature (2–8).
Methods
The questionnaire was developed by the members of
the ATA Clinical Affairs and Public Health Committees with
input from other ATA committees and individual members. The survey consisted of 27 questions across a range of
topics, including participant demographics, safety protocols,
screening practices, procreation, consent forms, insurance issues, and precautions for isolation, human contact, and hygiene. Respondents were also invited to submit additional
general comments, and their personal or institutional example
of patient instructions for I-131 treatment. A summary of the
questionnaire is provided in Figure 1 and the questionnaire is
included as supplementary data S1 (Supplementary Data are
available online at www.liebertonline.com/thy).
The questionnaire was included as a hyperlink in an e-mail
message to ATA members and to members of the American
Association of Endocrine Surgeons, who were encouraged to
forward this e-mail to their colleagues. The survey was
also presented to the leadership of the Society of Nuclear
FIG. 1.
Medicine and the American Society for Therapeutic Radiology and Oncology, but, to our awareness, was not distributed further. A link to the survey was placed on the Web sites
of The Endocrine Society and the American Association of
Clinical Endocrinologists. The survey was hosted by SurveyMonkey.com, an online ﬁrm providing questionnaire
services, including construction, hosting, and spreadsheet
summaries of responses. The responses were collected and
maintained anonymously. Duplicate entries or incomplete
responses were screened and excluded on the basis of Internet
Protocol addresses as a quality control measure. Not all respondents answered every question, and some respondents
provided answers more than once. In these cases, only the ﬁrst
response attributable to an Internet Protocol address was included in the analysis. If respondents chose more than one
answer for dosing questions, only the lowest dosage chosen
was counted. If ‘‘Do Not Advise’’ was selected, only that response was counted. For some analyses, the respondents were
divided into subsets based on role. Speciﬁcally, the data
summarized in Tables 5 and 6 provide the responses of those
practitioners who administer or supervise the treatment of
I-131, as the respondents who indicated that they only refer
patients for therapy did not elect to complete the questionnaire on these topics to allow subset-to-subset comparisons.
Also, under each heading of the Results section, any subset
analysis according to a provider’s role is addressed directly in
the context of the topic being presented.
Because the questionnaire was designed to quantify current
practices, the focus of this survey was on the identiﬁcation,
rather than a critical evaluation, of differences. To this end, the
statistics provided in the tables were limited to simple counts
and percentages relative to the total number of responses for
each question. Also, as noted in the Discussion section, because the distribution of the survey was to a broad audience of
diverse specialists, it was not possible to quantify a response
rate as a percentage of any speciﬁc denominator. At the time
Contents of the American Thyroid Association (ATA) I-131 safety recommendations survey.
I-131 CURRENT PRACTICES SURVEY
153
of survey distribution, there were 1300 members in ATA, 311
members in American Association of Endocrine Surgeons,
14,000 members in The Endocrine Society, and 6000 American
Association of Clinical Endocrinologists members. It was not
known how many clinicians are members of multiple organizations. In addition, some members of each society are engaged in basic research, in nonthyroidal ﬁelds (e.g., diabetes),
or may not prescribe or be licensed to administer I-131. As
no single organization or professional group exists whose
membership deals exclusively with clinical practice using I131, estimating an appropriate denominator was not feasible.
Results
A total of 311 individuals participated in the survey. The
number of patients treated annually with I-131 was between 10 and 100 for the majority of respondents (219/311,
70%), with an additional 46 specialists (15%) treating >100
patients annually. Half of the respondents (156/311, 50%)
indicated that they personally administer and supervise the
I-131 treatment. Most (207/311, 67%) also designated that
they themselves provided safety precautions related to I-131
therapy. Responses to questions contingent on the specialty
of the practitioner administering or supervising I-131 therapy
were analyzed for only those respondents who identiﬁed
themselves by group, so that the advice tabulated reﬂected
opinions within each treating specialty, rather than that of all
specialists who refer patients for I-131 therapy.
Demographic proﬁle of the survey respondents
The majority of respondents (260/311, 84%) identiﬁed
themselves as physicians and 51 (16%) were nonphysicians.
Medical specialties represented by the study respondents included endocrinologists (195, 63%), surgeons (31, 10%), nuclear medicine physicians (27, 9%), and a minority of others
(radiation oncology 2, pediatrics 3, unspeciﬁed 10). The majority of physicians (62%, 161/260) were afﬁliated with universities. In contrast, the majority of radiation safety ofﬁcers
(RSOs) were based in private practice (25/39, 66%). Nonphysician respondents consisted primarily of RSOs (39, 13%)
and rarely of nurse practitioners (1) and radiation safety
program coordinators (1).
Most respondents (252/301, 84%; 10 did not specify country of origin) were from North America, and 97% of the RSOs
were from the United States (Table 1). At least one endocri-
nologist from each of the geographic locations outside of
North America (South America, Europe, Middle East, and
Asia) provided a response; not all of these locations were represented in the group of surgeons and nuclear medicine
physicians. Professional afﬁliations identiﬁed by study participants reﬂected their specialties, and many respondents,
particularly endocrinologists, were members of multiple associations (Table 2).
Nature of experience with I-131 treatment
Regardless of specialty, most respondents (75%, 219/293)
were involved in radioiodine treatment, between 10 and 100
patients annually (Table 3). However, the personal administration or supervision of I-131 for hyperthyroidism, goiter, or
thyroid cancer varied depending on physician specialty.
Nearly all (93%) of the nuclear medicine physicians and 70%
of RSOs stated that they administered or supervised administration of I-131 for hyperthyroidism, goiter, or thyroid cancer, whereas only 50% of the endocrinologists and 10% of the
surgeons did so.
Safety instructions pertaining to isolation,
human contact, and hygiene
Providers of safety instructions. Responses to the question regarding the source of safety instructions for the patient
and family members revealed that the patients received instructions from a variety of sources and often from more than
one source. The majority of endocrinologists (85%) provided
instruction personally and/or within their practices, but 79%
also believed that safety instruction was given to patients in
the nuclear medicine department. In contrast, only 42% of
surgeons provided instruction personally, which may not be
surprising, given that 100% of the surgeons indicated such
instruction was provided in the nuclear medicine department
and 90% of surgeons identiﬁed their role as referring, rather
than directly treating, patients with I-131. Similar to the endocrinologists, a high proportion of nuclear medicine physicians provided instructions either personally or within their
nuclear medicine department (21/27, 78%), with an additional 37% (10/27) expecting further patient guidance from
RSO. The responses from RSOs revealed that 72% (28/39)
provided safety instruction to patients within their departments, and 74% of RSOs anticipated that radiation safety instruction would also be provided by the nuclear medicine
Table 1. Geographic Locations of 311 Respondents Participating in the American Thyroid
Association Survey of I-131 Safety Recommendations
Endocrinologist
Nuclear medicine
Surgeon
RSO
Other
Geographic area
n
%
n
%
n
%
n
%
n
%
North America
United States
Canada
Mexico
Othera
Totalb
148
6
5
35
194
76
3
3
18
19
2
2
4
27
70
7.5
7.5
15
25
0
0
6
31
81
0
0
19
38
0
0
1
39
97
0
0
3
7
0
0
3
10
70
0
0
30
a
The category ‘‘Other’’ included South America, Europe, Middle East, and Asia.
All respondents did not answer every question; 10 respondents did not state a country of origin.
RSO, radiation safety ofﬁcer.
b
154
GREENLEE ET AL.
Table 2. Professional Association Afﬁliations of 311 Respondents Participating in the American
Thyroid Association Survey of I-131 Safety Recommendations
Endocrinologist
Professional association
Nuclear medicine
Surgeon
RSO
Other
n
%
n
%
n
%
n
%
n
%
American Thyroid Association
American Association of Clinical Endocrinologists
The Endocrine Society
American Association of Endocrine Surgeons
Society of Nuclear Medicine
American Society for Therapeutic Radiology and Oncology
Other professional association
116
130
156
0
6
1
34
60
67
80
0
3
0.5
17
6
0
1
0
26
1
6
22
0
4
0
96
4
22
11
13
5
26
0
0
6
36
42
16
84
0
0
19
0 0
0 0
0 0
0 0
10 26
3 8
34 87
3
2
4
0
1
1
1
30
20
40
0
10
10
10
Total number of physiciansa
194
27
31
39
10
a
All respondents did not answer every question; 10 respondents did not state professional association.
n, number of physicians who indicated they were members of the association in question.
department. Of practitioners who indicated that, in their
clinical setting, more than one specialist provides safety instructions to patients and their family members, the majority
perceived that the recommendations from these sources were
comparable (Table 4). The proportion of those who indicated
that recommendations were comparable, however, varied
according to specialty type (Table 4A) and whether the
practitioner administers I-131 treatment (Table 4B). Of note,
3%–11% indicated that recommendations were not comparable, up to 16% did not know whether they were comparable,
and up to 45% provided written comments that could not be
readily categorized, but rather expressed broadly what the
specialists do in their practice.
Isolation precautions. To ascertain isolation precautions
for radioiodine treatment, survey questions asked were at
what dose and for how long patients were required to be
hospitalized, quarantined at home, and/or to stay at a hotel.
One-quarter (23%) of respondents indicated that they did
not use doses in the range between 7400 and 11,063 MBq (200–
299 mCi), and 50% indicated that they did not use a dose of
11,100 MBq (300 mCi) I-131 or higher. At or below 1110 MBq
(30 mCi), 72/104 (69%) of the respondents stated they never
hospitalize their patients (Fig. 2). At higher I-131 doses, proportionally fewer specialists never hospitalize (28% at dose
1147–3663 MBq [31–99 mCi]; 15% at dose 3700–7363 MBq
[100–199 mCi]; 6% at dose 7400–11,063 MBq [200–299 mCi]).
Similarly, the percentage of specialists who speciﬁed a duration of hospital stay increased with increasing doses of administered I-131 (5% at doses <1110 MBq [ <30 mCi]; 19%
at dose 1147–3663 MBq [31–99 mCi]; 20% at dose 3700–
7363 MBq [100–199 mCi]; 30% at dose 7400–11,063 MBq [200–
299 mCi]; 32% at dose >11,100 MBq [ > 300 mCi]). However,
across all dose ranges, specialists frequently stated that the
decision to hospitalize depended on the social situation; the
ATA questionnaire did not elaborate on what deﬁnes social
situations in these circumstances, and neither did the respondents. Likewise, for those recommending hospitalization
for doses over 3700 MBq (100 mCi), the length of stay was
dependent on patient radioactivity measurements, according
to 30% of respondents.
Recommendations for quarantine at home showed the following patterns: quarantine at home was never recommended by 51% of respondents for I-131 doses 1110 MBq
(30 mCi) and by 34% administering doses between 1147 and
3663 MBq (31–99 mCi). For respondents who recommended
that patients stay at home following treatment, the amount of
time recommended for staying at home increased progressively from <1 day to 72 hours, as the dose of radioiodine
increased beyond 7400 MBq (200 mCi).
Recommendations for a hotel stay to avoid contaminating
the home were rarely made: over 80% of respondents never
recommended a hotel stay for dose ranges below 11,063 MBq
(299 mCi). This was corroborated by several questions that
incorporated a choice for hotel stay.
Human contact precautions. Ten questions focused on
recommendations about human contact distance precautions
following radioiodine treatment, with duration options of 24,
24–48, or >48 hours after I-131 therapy. Responses indicated
Table 3. Numbers of Patients Treated or Referred for I-131 Treatment by 311 Respondents Participating
in the American Thyroid Association Survey of I-131 Safety Recommendations
<10
>100
10–100
Physician type
n
%
n
%
n
%
Totala
Endocrinologist
Nuclear medicine
Surgeon
Radiation safety ofﬁcer
Other
14
2
4
5
3
7
7
13
14
43
152
15
27
21
4
79
56
87
58
57
26
10
0
10
0
14
37
0
28
0
192
27
31
36
7
a
All respondents did not answer every question: 293 of 311 responded to this question.
I-131 CURRENT PRACTICES SURVEY
155
Table 4. Responses to the Question ‘‘Are Safety Recommendations from Multiple Sources Comparable?’’
by 311 Respondents Participating in the American Thyroid Association Survey
of I-131 Safety Recommendations
(A) Responses Grouped by Specialty
Yes
Physician type
Endocrinologist
Nuclear medicine
Surgeon
Radiation safety ofﬁcer
Other
a
No
Don’t know
Other
n
%
n
%
n
%
n
%
Totala
123
15
10
24
5
77
88
50
86
72
10
1
1
3
0
6
6
5
11
0
13
1
0
0
1
8
6
0
0
14
14
0
9
1
1
9
0
45
3
14
160
17
20
28
7
All respondents did not answer every question: 232 of 311 responded to this question.
(B) Responses Grouped by Whether Practitioner Administers or Supervises I-131 Treatment
Yes
No
Don’t know
Other
Role in I-131 treatment
n
%
n
%
n
%
n
%
Totala
Does not administer or supervise I-131 treatment
Administers or supervises I-131 treatment
73
97
69
83
11
4
10
3
17
7
16
6
5
9
5
8
106
117
a
All respondents did not answer every question: 223 of 311 responded to this question.
that there was little to no difference in the recommended
precautions as the time from I-131 treatment increased (Table 5
provides responses for the ﬁrst 24-hour interval).
Most respondents (84/105, 80%) recommended avoiding
children under age 2 for the ﬁrst 24 hours following treatment,
beginning at doses of radioiodine <1110 MBq (<30 mCi). A
further 12% recommended this avoidance for all doses at or
above 1110 MBq (30 mCi). In addition, starting at the lowest
dose range of 259–1073 MBq (7–29 mCi), over 60% of respondents recommended avoiding children under age 10
years, sexual contact, and breastfeeding. They also advised
sleeping alone, maintaining a speciﬁc distance from people,
and maintaining speciﬁc time/distance exposures, that is, the
length of time a person could spend within a certain distance
from a treated patient. Our questionnaire did not elicit what
those time/distance instructions were for each respondent.
FIG. 2. Type of isolation precautions according to treatment dose of I-131. The recommendation for hospitalization
includes any length of hospital stay. Dose of I-131 expressed
in MBq are as follows: 1110 MBq (30 mCi); 1147–3663 MBq
(31–99 mCi); 3700–7363 MBq (100–199 mCi); and 7400–
11,063 MBq (200–299 mCi).
Half of the respondents (49/106, 46%) recommended avoiding public transportation following doses of radioiodine
<1110 MBq (<30 mCi).
Half of the respondents recommended the same precautions for the ﬁrst 48 hours following treatment as for the ﬁrst
24 hours after treatment. Except for breastfeeding, contact
precautions beyond 48 hours were deemed to be unnecessary
by two to three times as many respondents as in the earlier
hours following treatment. Half of the respondents continued
to recommend avoidance of breastfeeding on the third day
posttreatment (over 48 hours).
At all time points, over 80% of respondents stated that they
did not advise the patients to stay in a hotel and did not
recommend potassium iodide (KI) for family members.
Hygiene precautions. Eight questions involved hygiene
precautions following radioiodine treatment, including recommendations regarding laundry and dental habits as well as
food preparation. Fewer respondents indicated that they offer
advice on toothbrush disposal and use of gloves for food
preparation, compared with other precaution categories.
The hygiene precautions listed in Table 6 summarize provider advice for the ﬁrst 48 hours after any level of I-131
treatment. The percentage of respondents who recommended
any one of the eight hygiene precautions was greater, by
margins of 1.3 or more, for those who actually administer or
supervise I-131 treatment, compared with any other practitioners. Approximately half of those who offered hygiene
precautions in the ﬁrst 24 hours following treatment did not
continue these precautions beyond 48 hours for patients
who had received I-131 in the dose range of 259–1073 MBq
(7–29 mCi).
Precautions relating to reproduction
Pregnancy screening practices. Most respondents (151/
168, 90%) indicated that they always screen for pregnancy
156
GREENLEE ET AL.
Table 5. Recommended Human Contact Precautions for the First 24 Hours After I-131 Treatment Provided
by 311 Respondents Participating in the American Thyroid Association Survey of I-131 Safety Recommendations
All doses
1110 MBq
(30 mCi)
All doses
3700 MBq
(100 mCi)
All doses
7400 MBq
(200 mCi)
Do not
advise
12 (11.3%)
Recommendation
na
259–1073 MBq
(7–29 mCi)
Avoid public transport?
Avoid children
<Age 2?
Ages 2–10?
Maintain a speciﬁc distance
with people?
Maintain a speciﬁc time/distance
exposure?b
Stay in a hotel?
Sleep alone?
Avoid sexual contact?
Avoid breast feeding?
Recommend KI for family members?
106
49 (46.2%)
34 (32%)
10 (9.4%)
1 (1%)
105
103
103
84 (80%)
69 (67%)
64 (62%)
19 (18%)
24 (23%)
23 (22%)
0 (0%)
3 (3%)
7 (7%)
1 (1%)
1 (1%)
1 (1%)
1 (1%)
6 (6%)
8 (8%)
103
68 (66%)
17 (17%)
7 (7%)
2 (2%)
9 (9%)
91
104
101
89
94
4
64
69
58
0
6
22
17
6
4
(4%)
(62%)
(68%)
(65%)
(0%)
(5%)
(21%)
(17%)
(7%)
(4%)
2
10
7
0
1
(2%)
(10%)
(7%)
(0%)
(1%)
3
3
2
1
0
(3%)
(3%)
(2%)
(1%)
(0%)
77
5
6
24
89
(85%)
(5%)
(6%)
(27%)
(95%)
All respondents did not answer every question, and respondents could select multiple answers among the recommendations. If
respondents chose multiple dosages, only the lowest dosage selected was counted. If ‘‘do not advise’’ was selected, only that response was
counted. For example, most respondents (84/105, 80%) recommended avoiding children under age 2 for the ﬁrst 24 hours following
treatment, beginning at doses of radioiodine between 259 and 1073 MBq (7–29 mCi). Another 18% recommended this avoidance start for all
doses at or above 1110 MBq (30 mCi).
a
Includes only respondents who answered yes (n ¼ 156 of 311, 50%) to the question ‘‘Do you administer or supervise administration of
I-131 for hyperthyroidism, goiter, or thyroid cancer?’’ All others were excluded (no ¼ 132, 42%; other ¼ 12, 4%; no response ¼ 11, 4%).
b
Deﬁned as a speciﬁed length of time during which a person was within a certain distance from a treated patient.
KI, potassium iodide.
nancy tests (8/11, 73%). Few respondents (3.6%) accepted
written consent of nonpregnancy status and few also (3.6%)
accepted verbal report of nonpregnancy.
The time between performing pregnancy screening and the
administration of I-131 was reported to be within 24 hours by
41% (82/198) and within 48 hours by 27% (53/198) of respondents. Few respondents (21/198, 11%) indicated that
they treated on the same day the pregnancy test was administered.
before giving I-131, with few doing this only sometimes (16,
9.5%); one respondent never did. Exclusion criteria for
screening for pregnancy included hysterectomy (165/207,
80%) and self-report of celibacy (7.2%). In response to an
open-ended question regarding pregnancy screening, a few
respondents answered that they also did not screen for
pregnancy if the patient was clearly postmenopausal or over
age 55.
Pregnancy screening was primarily accomplished with a
pregnancy test (179/194, 92%). Serum pregnancy tests were
most commonly employed by endocrinologists (111/156,
71%), nuclear medicine physicians (14/16, 88%), and RSOs
(15/23, 65%). Surgeons primarily reported using urine preg-
Timing of parenthood after I-131. Only a subset of respondents who reported administering or supervising administration of I-131 treatment answered questions relating to
Table 6. Recommended Hygiene Precautions for the First 48 Hours After I-131 Treatment Provided by 311
Respondents Participating in the American Thyroid Association Survey of I-131 Safety Recommendations
Recommendation
na
Wash hands frequently?
Dispose of toothbrush?
Wash clothes/bedding separate from family?
Wash dishes separate from family?
Do not make food for other people?
Wear gloves to prepare food?
Sit to void urine and always ﬂush twice?
Special precautions if emesis/incontinence occur?
102
98
101
100
98
92
95
103
259–1073 MBq
(7–29 mCi)
72
30
56
53
50
23
78
69
(71%)
(31%)
(55%)
(53%)
(51%)
(25%)
(82%)
(67%)
All doses
1110 MBq
(30 mCi)
11
13
20
18
19
14
19
16
(11%)
(13%)
(20%)
(18%)
(19%)
(15%)
(11%)
(16%)
All doses
3700 MBq
(100 mCi)
3
3
7
6
7
4
4
3
(3%)
(3%)
(7%)
(6%)
(7%)
(4%)
(4%)
(3%)
All doses
7400 MBq
(200 mCi)
1
1
1
1
1
1
1
1
(1%)
(1%)
(1%)
(1%)
(1%)
(1%)
(1%)
(1%)
Do not
advise
15
51
17
22
21
50
2
14
(15%)
(52%)
(17%)
(22%)
(21%)
(54%)
(2%)
(14%)
All respondents did not answer every question, and respondents could select multiple answers among the recommendations. If
respondents chose multiple dosages, only the lowest dosage selected was counted. If ‘‘do not advise’’ was selected, only that response was
counted.
a
Includes only respondents who answered yes (n ¼ 156 of 311, 50%) to the question ‘‘Do you administer or supervise administration of
I-131 for hyperthyroidism, goiter, or thyroid cancer?’’ All others were excluded (no ¼ 132, 42%; other ¼ 12, 4%; no response ¼ 11, 4%).
I-131 CURRENT PRACTICES SURVEY
157
Table 7. Recommended Delay Time Before Pregnancy Following I-131 Treatment Provided by 311
Respondents Participating in the American Thyroid Association Survey of I-131 Safety Recommendations
Recommendation
Respondents (n)a
1 month
3 months
6 months
12 months
No routine recommendation
1110 MBq
(30 mCi)
1147–3663 MBq
(31–99 mCi)
3700–7363 MBq
(100–199 mCi)
7400–11,063 MBq
(200–299 mCi)
11,100 MBq
(300 mCi)
108
3 (3%)
14 (13%)
57 (53%)
20 (19%)
14 (13%)
106
3 (3%)
8 (8%)
57 (54%)
32 (30%)
6 (6%)
106
1 (1%)
9 (8%)
50 (47%)
40 (38%)
6 (6%)
94
1 (1%)
7 (7%)
36 (38%)
41 (44%)
9 (10%)
89
0 (0)
7 (8%)
32 (40%)
40 (45%)
10 (11%)
a
All respondents did not answer every question.
recommendations restricting procreation after radioiodine
administration (108/156, 69%; Table 7). Of these respondents,
fewer provided responses to the questions regarding highdose-range treatments. The majority of respondents recommended that female patients who received doses below
7400 MBq (200 mCi) wait a minimum of 6 months before attempting pregnancy and at least 1 year for higher doses. At
least one-third of these respondents did not make recommendations to their male patients regarding delay times before fathering children (Table 8). When recommendations
were made, these were more often to wait for 6 months. The
proportion of respondents who chose to recommend a 12month delay until pregnancy increased incrementally as the
dose of I-131 treatment increased (e.g., 19% recommended
this for I-131 dose <1110 MBq [ <30 mCi], 38% for doses between 3700 and 7363 MBq [100–199 mCi], and 45% for doses
at or above 11,100 MBq [300 mCi], as shown in Table 7).
Use of consent forms
More than half (66%) of respondents stated that they use
consent forms for I-131 administration (Fig. 3). Most consent
forms provided information on pregnancy and breastfeeding
avoidance. Information on risk to salivary glands was also
present on most consent forms.
practitioners. The impact of insurance coverage in the United
States varied by geographical region (Fig. 4), with those
practicing in southern and western states responding that
payer insurance had more inﬂuence on choices of inpatient
versus outpatient I-131 care. The survey was not structured to
identify other outcomes related to insurance coverage.
Other geographical and specialty-based variations
in I-131 precautions
Although no comprehensive pattern of differences emerged
about I-131 safety recommendations, practice patterns varied
somewhat across specialty afﬁliations and geographic locations. Consent forms were more likely to be used by physicians in the United States (72% vs. 38% for all other countries)
and by nuclear medicine radiologists (88%) and RSOs (91%)
than endocrinologists and surgeons (58% each). Nuclear
medicine physicians were more than twice as likely to provide
speciﬁc recommendations to male patients about delaying
child-bearing and more likely to advise a longer duration of
delay at each of the I-131 dose ranges than were endocrinologists. This difference in recommendations between specialists did not exist for female patients and for either gender of
patients among those practicing within compared with outside the United States.
Discussion
Impact of payer status or insurance coverage
on I-131 precautions
The inﬂuence of insurance coverage on outpatient versus
inpatient care was felt to be a factor in decisions by 17% (26/
155) of the United States and 20% (7/35) of non-United States
This is a unique multidisciplinary survey that addressed
the topic of safety-related information provided to patients
receiving I-131 treatment for thyroid disorders. It queried
how various professionals convey I-131 safety precautions at
Table 8. Recommended Delay Time Before Fathering Children Following I-131 Treatment Provided by 311
Respondents Participating in the American Thyroid Association Survey of I-131 Safety Recommendations
Recommendation
Respondents (n)a
1 month
3 months
6 months
12 months
No routine recommendation
a
1110 MBq
(30 mCi)
1147–3663 MBq
(31–99 mCi)
3700–7363 MBq
(100–199 mCi)
7400–11,063 MBq
(200–299 mCi)
11,100 MBq
(300 mCi)
108
6 (6%)
14 (13%)
36 (33%)
8 (7%)
44 (41%)
106
2 (2%)
16 (15%)
36 (34%)
13 (12%)
39 (37%)
68
2 (3%)
13 (19%)
36 (53%)
17 (25%)
38 (56%)
96
2 (2%)
10 (10%)
30 (31%)
17 (18%)
37 (39%)
91
2 (2%)
8 (8%)
29 (32%)
15 (16%)
37 (40%)
All respondents did not answer every question.
158
FIG. 3. Use and composition of consent forms for I-131
treatment.
a level of detail that, to our knowledge, had not been accomplished in prior surveys or from predominantly the United States-based clinicians. Only few reports related to I-131
safety practices exist in the literature, some conducted in
Europe with more limited scope of questions, smaller respondent numbers, and less multidisciplinary breadth (9,10).
Based on the survey responses, our hypothesis was not rejected: I-131 safety practices do indeed vary widely. Radiation
safety instruction is presently available from a variety of
sources, and patients often receive information from more
than one source. In this study, we conﬁrmed the perception
from prior work (2,11,12) that notable differences in recom-
FIG. 4. Proportion of specialists who indicated that insurance status inﬂuenced outpatient versus inpatient therapy
with I-131.
GREENLEE ET AL.
mendations exist nationally among the various professionals
involved in the therapeutic administration of I-131. Our
analysis showed that most survey respondents provided little
consistency in practice patterns and radiation safety recommendations from various sources, suggesting the potential for
patient and staff confusion. It may seem reasonable to expect
that, as the surgeons’ responses imply, all instruction ultimately resides with a nuclear medicine department. But
clearly, neither the nuclear medicine radiologists nor the RSO
responders indicated that this actually occurs. Our questionnaire was not structured to conﬁrm who ultimately does
provide such safety instruction.
An area of signiﬁcant concern to patients receiving I-131
therapy is the site where that treatment will occur. Our survey showed that hospitalization was rarely recommended for
I-131 doses 1110 MBq (30 mCi). Hospitalization recommendations were also inﬂuenced by the type of insurance
coverage and varied by geographic region within the United
States. For the dose range 1147–7363 MBq (31–199 mCi), the
recommendation to hospitalize was a function of patient radioactivity measurement and/or social situations, although
the survey did not inquire further about the speciﬁc thresholds of radioactivity measurement or examples of social situations that prompt the recommendation to hospitalize
following I-131 treatment.
Another broad topic of concern to patients and providers
alike is the scope of contact precautions after I-131 treatment.
The types of recommendations reported included avoiding
children under age 10 years and sexual contact for the ﬁrst
3 days following treatment, sleeping alone, maintaining a
speciﬁc distance from people, and limiting time spent with
others. More respondents recommended contact precautions
during the ﬁrst 24 and 48 hours posttreatment than at 3 days
following I-131 treatment. Avoidance of public transportation
was most commonly recommended only for the ﬁrst 24 hours
after treatment. Only 70% of respondents who provided
safety precautions provided information to their patients regarding delaying starting a family. Recommendations relative to timing for future conception were given more often and
had more consistent precautions when treating women than
men. These patterns suggest a real need for deﬁning more
consistent and clear recommendations for radiation safety
precautions. Such recommendations have the potential to
streamline the educational obligations of providers of I-131
treatment, enhance patient understanding, and reduce patient
anxiety related to daily activities following I-131 treatment.
Regardless of the administered radioiodine dose level,
staying in a hotel was not recommended by the vast majority
of respondents. This was determined through two questions,
one inquiring about the dose at which a hotel stay was recommended to avoid home contamination and the second
through the option of answering ‘‘staying in a hotel’’ as part of
human contact precautions; the majority of respondents indicated that they did not advise this step. There is currently no
known policy for accommodating such patients that is stated
by the American Hotel and Lodging Association (13) and,
from anecdotal experiences described during the survey, no
mechanism for hotel management to be made aware that a
patient with recent I-131 treatment is a guest.
Several limitations of the study can be identiﬁed. Respondents were self-selected, based on survey access and
motivation to respond. Responses reﬂected the individual
I-131 CURRENT PRACTICES SURVEY
practices of respondents, which may not necessarily represent
practices of other practitioners involved in radioiodine administration. These survey responses may also not represent
best practices for such treatment. We acknowledge that our
study, similar to other online surveys, cannot provide an accurate total denominator of individuals who received the
questionnaire but did not complete or return it. The enormous
membership rosters of the societies that received this questionnaire preclude this calculation and also make it cumbersome to model nonresponse bias in our study. This is the ﬁrst
survey of its kind, with over 300 respondents from a variety of
disciplines, reﬂecting the interest and the reality of multidisciplinary involvement with I-131 treatment. The study provides a cross-sectional view of the I-131 safety instructions in
use today, with enough responses to reﬂect the wide variation
in I-131 safety practices. Although the study addressed dose
ranges for radioiodine, no distinction was made between
treatments for hyperthyroidism, goiter, or thyroid cancer.
We did not inquire about recommendations beyond 3 days
posttreatment, and it is possible that recommendations
against breastfeeding would extend beyond that time as a
function of higher treatment dose. Menopause and age were
not options provided in the pregnancy screening exclusion
question, so it is possible these answers were underrepresented. We also noted that answers to questions involving
dose ranges typically yielded fewer responses for the higher
dose ranges than the lower ranges, perhaps because respondents assumed their answers involving lower doses extended
to the higher doses. A potential weakness of the question regarding staying at home was that it did not differentiate between I-131 dose for outpatient treatment versus inpatient
treatment (during which time, elimination and decay of radioisotope was expected during hospitalization). To better
deﬁne isolation practices in any future study, it would be
helpful to specify such details.
In conclusion, we conducted a survey of groups of selfselected respondents involved in the administration of therapeutic I-131. We observed a wide range of safety practices
and recommendations and the perception of conﬂicting information offered to patients. These differences may reﬂect a
lack of best practices based on scientiﬁc data. Guidelines reﬂecting expert opinion, evidence-based decision-making, and
further investigation would be useful, and our survey results
may provide an opportunity to stimulate development of
such recommendations.
Acknowledgments
The authors acknowledge the 2006–2009 American Thyroid Association Clinical Affairs Committee, Public Health
Committee, and Radioactive Iodine Best Practices Task Force
members and administrative staff for their contributions.
Disclosure Statement
The authors declare that no competing ﬁnancial interests
exist.
159
References
1. National Council on Radiation Protection and Measurements 2006 Management of Radionuclide Therapy Patients.
NCRP Report No. 155. National Council on Radiation Protection and Measurements, Bethesda, MD.
2. Sparks RB, Siegel JA, Wahl RL 1998 The need for better
methods to determine release criteria for patients administered radioactive material. Health Phys 75:385–388.
3. Grigsby PW, Siegel BA, Baker S, Eichling JO 2000 Radiation
exposure from outpatient radioactive iodine (131I) therapy
for thyroid carcinoma. JAMA 283:2272–2274.
4. Barrington SF, O’Doherty MJ, Kettle AG, Thomson WH,
Mountford PJ, Burrell DN, Farrell RJ, Batchelor S, Seed P,
Harding LK 1999 Radiation exposure of the families of
outpatients treated with radioiodine (iodine-131) for hyperthyroidism. Eur J Nucl Med 26:686–692.
5. Carey JL, Kumpuris TM, Wrobel MC 1995 Release of
patients containing therapeutic dosages of iodine-131 from
hospitals. J Nucl Med Technol 23:144–149.
6. Ibis E, Wilson CR, Collier BD, Akansel G, Isitman AT, Yoss
RG 1992 Iodine-131 contamination from thyroid cancer patients. J Nucl Med 33:2110–2115.
7. Barrington SF, Anderson P, Kettle AG, Gadd R, Thomson
WH, Batchelor S, Mountford PJ, Harding LK, O’Doherty MJ
2008 Measurement of the internal dose to families of outpatients treated with (131)I for hyperthyroidism. Eur J Nucl
Med Mol Imaging 35:2097–2104.
8. Thomson WH, Harding LK 1995 Radiation protection issues
associated with nuclear medicine out-patients. Nucl Med
Commun 16:879–892.
9. Vaidya B, Williams GR, Abraham P, Pearce SH 2008
Radioiodine treatment for benign thyroid disorders: results
of a nationwide survey of UK endocrinologists. Clin Endocrinol 68:814–820.
10. Monsieurs M, Thierens H, Dierckx RA, Casier K, De Baere E,
De Ridder L, De Saedeleer C, De Winter H, Lippens M, van
Imschoot S, Wulfrank D, Simons M 1998 Real-life radiation
burden to relatives of patients treated with iodine-131: a
study in eight centres in Flanders (Belgium). Eur J Nucl Med
25:1368–1376.
11. Woodings S 2004 Radiation protection recommendations for
I-131 thyrotoxicosis, thyroid cancer and phaeochromocytoma patients. Australas Phys Eng Sci Med 27:118–128.
12. Dietlein M, Troche CJ, Moka D, Bausch V, Lauterbacj KW,
Schicha H 1998 Consequences of new patient discharge
guidelines on the cost structure of radioiodine therapy.
Nuklearmedizin 37:33–40.
13. American Hotel and Lodging Association. Available at
www.ahla.com/. Accessed October 26, 2010.
Address correspondence to:
Carol Greenlee, M.D.
Western Slope Endocrinology
603 28 1/2 Road
Grand Junction, CO 81505
E-mail: [email protected]
(Appendix follows ?)
160
Appendix: American Thyroid Association I-131
Safety Recommendations Questionnaire
1. What type of professional are you? (endocrinologist,
nuclear medicine physician, radiation oncologist, surgeon, pediatrician, internist, family practitioner, nurse
practitioner, physician’s assistant, other-please specify)
2. Which professional associations do you belong to?
(American Thyroid Association, American Association
of Clinical Endocrinologists, The Endocrine Society,
American Association of Endocrine Surgeons, Society of
Nuclear Medicine, American Society of Therapeutic
Radiology and Oncology, other-please specify)
3. In what state/country do you practice?
4. Do you refer patients with hyperthyroidism, goiter, or
thyroid cancer to receive radioactive iodine? (yes/no/
other)
5. Do you administer or supervise administration of I-131
for hyperthyroidism, goiter, or thyroid cancer? (yes/
no/other)
6. Please select the setting that you practice in? (academic/university environment, ‘‘pure’’ private practice,
private practice with adjunct university appointment,
other-please specify)
7. How many patients a year do you treat with I-131 or
refer for I-131 treatment? (<10, 10–100, >100)
8. Who provides the safety instructions to the patient/
family? Check all that apply. (me/my practice, nuclear
medicine department, radiation safety department,
other-please specify)
9. If you marked more than one in Q8, are the recommendations/instructions comparable? (yes/no/don’t
know/other-please specify)
For questions 10–12, the questions were posed in tabular form
with the following I-131 dose ranges each having these answer choices: hospitalized 24 hours, hospitalized 48 hours,
hospitalized 72 hours, dependent on patient radioactivity
measurement, do not use this dose, never hospitalize, depends on social situation, other. A space was also made
available for write-in comments.
I-131 dose ranges were 1110 MBq (30 mCi), 1147–
3663 MBq (31–99 mCi), 3700–7363 MBq (100–199 mCi), 7400–
11,063 MBq (200–200 mCi), 11,100 MBq (300 mCi).
10. At what doses do you hospitalize?
11. At what doses do you recommend a stay in a hotel to
avoid contamination of home?
12. At what doses do you recommend that the patient stay
at home after treatment or after release from the hospital as an inpatient?
For questions 13–15, respondents were asked to indicate what
human contact precautions were made for each of the dose
ranges speciﬁed above for questions 10–12. The types of
precautions queried included the following: avoid public
transportation, avoid children under 2 years old, avoid children 2–10 years old, stay in hotel, sleep alone, avoid sexual
contact, maintain speciﬁc distance with people, maintain
speciﬁc time/distance exposure, breast feeding, use of potassium iodide to protect family members. Respondents could
GREENLEE ET AL.
also select that they do not advise a particular precaution and
submit a write-in comment.
13. What human contact precautions do you advise on
day 1 (ﬁrst 24 hours) following I-131 treatment?
14. What human contact precautions do you advise on
day 2 (24–48 hours) following I-131 treatment?
15. What human contact precautions do you advise on
day 3 and beyond (over 48 hours) following I-131
treatment?
For questions 16–18, respondents were asked to indicate what
hygiene precautions were made for each of the dose ranges
speciﬁed above for questions 10–12. The types of precautions
queried included the following: cleanliness: wash hands frequently; cleanliness: dispose of toothbrush; cleanliness: wash
bedding and clothes separate from family; cleanliness: wash
dishes separate from family; food preparation: don’t make
food for other people; food preparation: wear gloves to prepare food; toilet use: sit to void urine and always ﬂush twice;
waste/emesis clean-up. Respondents could also select that
they do not advise a particular precaution and submit a writein comment.
16. What hygiene precautions do you advise on day 1
(ﬁrst 24 hours) following I-131 treatment?
17. What hygiene precautions do you advise on day 2 (24–
48 hours) following I-131 treatment?
18. What hygiene precautions do you advise on day 3 and
beyond (over 48 hours) following I-131 treatment?
19. Do you screen for pregnancy before giving I-131 to
women? (always, sometimes, never, other-please
specify)
20. After screening for pregnancy, how much time before
giving I-131 treatment? (24 hours, 48 hours, otherplease specify)
21. What exclusions do you allow for not screening in
women of childbearing age? (hysterectomy, self-report
of celibacy, no exclusions, other-please specify)
22. What tests do you use? (serum pregnancy test, urine
pregnancy test)
23. Which do you require? (pregnancy test results, written
consent of no pregnancy, verbal report of no pregnancy, none, other-please specify)
For questions 24–25, respondents were asked to indicate how
long after I-131 to avoid child reproduction, for each of the
doses speciﬁed above for questions 10–12. The answer selections included 1 month, 3 months, 6 months, 12 months, or
that no routine recommendation was provided.
24. How long do you recommend that female patient
avoid pregnancy after I-131 treatment?
25. How long do you recommend that male patients avoid
fathering a child?
26. Do you use a consent form (yes/no)? If yes, does it
contain information about avoidance of pregnancy
(yes/no), breast feeding (yes/no), risk of malignancy
(yes/no), risk to salivary glands (yes/no), other
(please specify)?
27. Does insurance affect choice of outpatient versus inpatient care? (yes/no/other-please specify)